The present invention relates generally to a keel structure for use in sailboats, and more particularly to a keel structure which has improved hydrodynamic characteristics and properties.
Keels are requisite components of sailboats, and are utilized for the purposes of contributing to the forward motion of the sailboat, as well as to stability of the craft while underway. In order to provide the forward motion, the keel must present a relatively large profile or lateral surface to the water, with the area of the keel which is exposed or presented to the water being a factor in the force which the wind generates to provide forward motion for the craft. Because of their size, and necessary or essential cross-sectional dimension, a certain amount of resistance to forward motion is provided by the presence of the submerged keel.
The present invention provides a means for reducing the resistance to motion by reducing the amount of turbulence, eddies, and cavitation which would otherwise be created by the motion of the keel moving through the water. Keel structures are generally elliptical in cross-section, with the elliptical cross-section having been found in the past to provide a reduction in the turbulence, eddies and cavitation. In accordance with the present invention, however, an elongated slotted opening is formed along the aft edge of the keel and extends forwardly to a point aft of the minor axis of the elliptically configured body so as to create an internal chamber in the keel body. A plurality of bores are formed in the keel body and extend diagonally from forward ports along the outer surface of the keel to aftward ports along the inner surfaces of the internal chamber. It has been determined that the presence of the openings in the keel create a vacuum action with passage of water through the bores, thus reducing the creation of turbulence, generation of eddies, and cavitation in the water as the craft moves along its course.